The Making of the Atomic Bomb

1
The Making of the Atomic Bomb

• Trinity Test, July 16, 1945

2
Scientific Background

• Discovery of Nuclear Fission, 1938-1939
• Upon Meitners recommendation, Hahn and Strassman
  reexamined their earlier belief and came to the
  conclusion that barium, rather than radium, was
  created when bombarding uranium with neutrons
• Meitner and Frisch used liquid drop model to
  explain fission http//dbhs.wvusd.k12.ca.us/webdo
  cs/Chem-History/Meitner-Fission-1939.html

3
Possibility of Bomb

• Leo Szilard chain reactions
• Fermi and Szilard experiment at Columbia U.
• Einsteins letter to FDR, 1939
• Uranium Committee
• Turning point 1940 Peierls-Frisch calculation of
  small critical mass of arrived in the US in 1941

4
Research and Production

• FDR authorized large-scale uranium research the
  day before Pearl Harbor
• Manhattan Project September 1942 when Gen.
  Leslie Groves took over
• Chicago Pile 1 Nuclear reactor under Fermi
  proved chain reaction in late 1942
• Plutonium route
• Production sites Oak Ridge and Hanford

5
Los Alamos Assembling the Bomb

• J. Robert Oppenheimer as director
• Collaboration of scientists from many
  countriesdemocratic strength?
• Maintain production schedule
• Gun-type for uranium bomb
• Implosion for plutonium bomb
• Trinity test in July 1945
• Scientists views on the making of the bomb

6
Science and the Bomb

• Big Science team work, interdisciplinary nature,
  large, government funding, political dimensions
• Scientists social responsibility
• New pattern of both the support and use of
  science by governments